/* ----------------------------------------------------------
   AnyCoder AI — unified dark‑mode design system
   ---------------------------------------------------------- */

:root {
  --bg:            #0d1117;
  --bg-secondary:  #161b22;
  --border:        #30363d;
  --text:          #c9d1d9;
  --text-muted:    #8b949e;
  --accent:        #58a6ff;
  --accent-hover:  #79c0ff;
  --danger:        #f85149;
  --success:       #56d364;
  --radius:        8px;
  --transition:    0.2s ease;
  --font-mono:     "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
}

/* ============= 1. Global reset & typography ============= */
*,
*::before,
*::after { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

h1, h2 { font-weight: 600; }

/* ============= 2. Layout blocks ============= */
main {
  max-width: 900px;
  margin: 0 auto;
  display: grid;
  gap: 2rem;
  padding: 1rem;
}

section {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
}

/* ============= 3. Forms & controls ============= */
label { font-weight: 600; }

select,
input[type="file"],
input[type="url"],
textarea {
  width: 100%;
  padding: 0.75rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg);
  color: var(--text);
  font-size: 1rem;
  transition: border-color var(--transition);
}

select:focus,
input:focus,
textarea:focus { outline: none; border-color: var(--accent); }

textarea {
  resize: vertical;
  min-height: 120px;
  font-family: var(--font-mono);
}

/* ============= 4. Tabs ============= */
.tabs { display: flex; gap: 0.5rem; margin-bottom: 1rem; }

.tabs button {
  background: transparent;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.5rem 1rem;
  color: var(--text-muted);
  cursor: pointer;
  transition: background var(--transition), color var(--transition);
}

.tabs button[aria-selected="true"] {
  background: var(--accent);
  color: var(--bg);
  border-color: var(--accent);
}

.tabs button:hover:not([aria-selected="true"]) {
  background: var(--border);
  color: var(--text);
}

/* ============= 5. Action buttons ============= */
.actions { display: flex; gap: 1rem; justify-content: flex-end; }

button {
  padding: 0.75rem 1.5rem;
  border: none;
  border-radius: var(--radius);
  font-size: 1rem;
  cursor: pointer;
  transition: background var(--transition);
}

#clear { background: var(--border); color: var(--text); }
#clear:hover { background: var(--text-muted); }

#generate { background: var(--accent); color: var(--bg); }
#generate:hover { background: var(--accent-hover); }

/* ============= 6. Output areas ============= */
pre {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.9rem;
}

iframe {
  width: 100%;
  height: 400px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: #fff;
}

/* ============= 7. Accessibility helpers ============= */
.visually-hidden {
  position: absolute !important;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

/* ============= 8. Responsive tweaks ============= */
@media (max-width: 600px) {
  main  { padding: 0.5rem; }
  h1    { font-size: 2rem; }
  .actions { flex-direction: column; }
}